Connection surface for a structural unit

ABSTRACT

A connection surface that is disposed on at least a portion of a face of a structural unit comprises a first convex surface and a first concave surface arranged substantially along a first line. The shape of the first concave surface is complementary to the shape of the first convex surface. A second convex surface and a second concave surface are arranged substantially along a second line that is substantially parallel to the first line. The shape of the second concave surface is complementary to the shape of the second convex surface. The concave-convex order of the second line is reversed relative to the first line, such that the second convex surface corresponds with the first concave surface and the second concave surface corresponds with the first convex surface.

PRIORITY CLAIM

This application claims priority of U.S. Provisional Application Ser. No. 61/727,472, filed Nov. 16, 2012.

FIELD OF THE INVENTION

The subject disclosure relates to pavers, edgers, wall blocks, curbs, caps, precast wall panels, revetment mats, and other structural units, and in particular to connectors for structural units.

BACKGROUND OF THE INVENTION

It is well known to construct pavers, edgers, walls, curbs, caps, precast wall panels, revetment mats, and other structures with structural units. Such structural units can be manufactured from concrete, clay, brick, plastic, or various other materials.

SUMMARY OF THE INVENTION

An embodiment of the invention provides a connection surface that is disposed on at least a portion of a face of a structural unit. The connection surface comprises a first convex surface and a first concave surface arranged substantially along a first line. The shape of the first concave surface is complementary to the shape of the first convex surface. A second convex surface and a second concave surface are arranged substantially along a second line that is substantially parallel to the first line. The shape of the second concave surface is complementary to the shape of the second convex surface. The concave-convex order of the second line is reversed relative to the first line, such that the second convex surface corresponds with the first concave surface and the second concave surface corresponds with the first convex surface.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a top plan view of two connected structural units according to a first embodiment of the invention.

FIG. 2 a is a sectional view of the connected structural units of FIG. 1, taken along line A-A and in the direction indicated.

FIG. 2 b is a sectional view of the connected structural units of FIG. 1, taken along line B-B and in the direction indicated.

FIG. 3 a is an end view of one of the structural units of FIG. 1.

FIG. 3 b is an end view of another of the structural units of FIG. 1.

FIGS. 4-5 are perspective views of a second embodiment structural unit.

FIG. 6 is a perspective view of a third embodiment structural unit.

FIG. 7 is a perspective view of two of the third embodiment structural units with connection surfaces facing one another.

FIG. 8 is a perspective view of a fourth embodiment structural unit having a beveled edge.

FIG. 9 is a perspective view of a fifth embodiment structural unit having irregular edges to provide a more natural stone appearance.

FIGS. 10-11 are perspective views of two fifth embodiment structural units with connection surfaces facing one another, with different ends of a second structural unit shown in FIGS. 10 and 11 respectively.

FIG. 12 is a perspective view of two of the fifth embodiment structural units connected end-to-end to form an angle.

FIG. 13 is a perspective view of two of the fifth embodiment structural units connected end-to-end to form a straight line.

FIG. 14 is a perspective view of one end of a wall section including two courses of the fifth embodiment structural units (the bottom rear structural unit is obscured) stacked in a half-bond arrangement.

FIG. 15 is a perspective view of an opposing end of the wall section of FIG. 14.

FIG. 16 is a front end perspective view of the wall section of FIG. 14.

FIG. 17 is a front perspective view of the wall section of FIG. 14.

FIG. 18 is a top perspective view of two trapezoidal structural units according to a sixth embodiment with connection surfaces facing one another.

FIG. 19 is a perspective view of the two sixth embodiment structural units connected end-to-end to form a straight line, where one of the structural units is reversed in orientation.

FIG. 20 is a close-up perspective view of the connection surfaces of the two sixth embodiment structural units.

FIG. 21 is a perspective view of the two sixth embodiment structural units with connection surfaces facing one another, where both of the structural units have the same orientation.

FIG. 22 is a perspective view of the two sixth embodiment structural units of FIG. 21 connected end-to-end to form a curve.

FIGS. 23 a-23 b are perspective views of a seventh embodiment structural unit having edges of convex portions that are partially beveled.

FIGS. 24 a-24 c are perspective views of an eighth embodiment structural unit having edges of convex portions that are separated by a distance.

FIG. 25 is a perspective view of two ninth embodiment structural units having connection surfaces with three-dimensional shaped convex portions.

FIG. 26 is a perspective view of two tenth embodiment structural units having connection surfaces with arch-shaped convex portions.

FIG. 27 is an elevation view of a portion of an eleventh embodiment wall having cruciform shaped structural units.

FIG. 28 is an elevation view of a portion of a twelfth embodiment wall having hexagonal shaped structural units.

FIG. 29 is an elevation view of a portion of a thirteenth embodiment wall having glide shaped structural units.

FIG. 30 is a plan view of three fourteenth embodiment paving units connected and arranged in a 90/90/180 irregular rotation arrangement, and showing areas of connection using connection surfaces.

FIG. 31 is a perspective view of a fifteenth embodiment structure including irregular rock connection surfaces.

FIG. 32 is a perspective view of a wall connected to a pavement according to a sixteenth embodiment, in which wall blocks and paving units include connection surfaces that connect to one another.

FIG. 33 is a perspective view of a seventeenth embodiment structural unit having a connection surface disposed on a substantially central interior portion of an end face.

FIG. 34 is a perspective view of a portion of a wall according to an eighteenth embodiment including rotated panels connected to one another by connection surfaces disposed on side faces.

FIG. 35 is a perspective view of an end face of a block according to a nineteenth embodiment having a pair of connection surfaces that are center rotations of one another about a centerline.

FIG. 36 is a perspective view of a structural unit according to a twentieth embodiment having a pair of connection surfaces including a central connection surface disposed along a centerline of a side face and an outer connection surface that is split and disposed nearer to edges of the side face.

FIG. 37 is a perspective view of a structural unit according to a twenty-first embodiment having two sets of connection surfaces on a single end face to provide insets and offsets.

FIG. 38 is a perspective view of a portion of a connection surface according to a twenty-second embodiment, in which the convex and concave surfaces are arranged to allow offsetting in a wall either backward or forward with triple sets.

FIG. 39 is a plan view of a connection surface according to a twenty-third embodiment, in which the convex surfaces are domed and separated from concave surfaces by a space.

FIG. 40 is a plan view of a connection surface according to a twenty-fourth embodiment, in which the convex surfaces are truncated pyramids.

FIGS. 41A and 41B are elevation views of two connected convex surfaces of adjacent structural units according to a twenty-fifth embodiment including external connection surfaces disposed thereon.

FIG. 42 is an elevation view of a convex surface and a concave surface of adjacent structural units according to a twenty-sixth embodiment including external connection surfaces disposed thereon.

FIG. 43 is a section view of two adjacent structural units according to a twenty-seventh embodiment in which connection surfaces are configured to allow movement in one direction, but restrict movement in another.

DETAILED DESCRIPTION

Embodiments of the invention provide, among other things, a connection surface disposed on at least a portion of a face of a structural unit. Structural units, structures including structural units, and methods for connecting structural units are also provided herein. It will be understood that illustration and description of connection structures will be applicable to illustrate and describe connecting methods, and vice versa. “Structural unit” refers to any unit that can used to form part of a structure. A preferred structural unit is a concrete building unit, including but not limited to pavers, concrete masonry units, retaining wall blocks, patio stones, pavers, edgers, curbs, caps, precast wall panels, and revetment mats.

Turning now to the drawings, FIGS. 1-3 illustrate a first embodiment of the invention. First and second structural units, namely blocks 10, 12 are shown having joined connection surfaces. Block 10 includes a connection surface having vertical halves 14, 16 on a face of the block 10, and block 12 includes a connection surface having vertical halves 18, 20 on the face of the block 12. As used herein, a connection surface “on” a face of a structural unit is intended to refer to a location on and/or in (partially or fully) the face of the structural unit.

FIG. 3 a depicts the connection surface of the first block 10. The connection surface includes a first convex surface 44 and a first concave surface 40, extending substantially along a first horizontal line. The first concave surface 40 in this embodiment has an inward “V” shaped profile, and the first convex surface 44 has an outward “V” shaped profile that is complementary to the first concave surface. As used herein the term “complementary” means that the two surfaces have substantially the same configuration such that a convex surface of one unit can be at least partially received within a complementary concave surface of another unit. The “complementary” surfaces need not be identical. Extending along a second horizontal line that is parallel to the first horizontal line are a second convex surface 42 and a second concave surface 46. The second convex surface 42 has an outward “V” shaped profile, and the second concave surface has a complementary shaped inward “V” shaped profile. The first block 10 also has upper and lower flat surfaces 48, 49, such that the connection surface is disposed on an interior portion of the block face. In the first block 10, the first concave surface 40 is also complementary to the shape of the second convex surface 42, and the second concave surface 46 is also complementary to the first convex surface 44, though this is not required in all embodiments.

As further shown in FIG. 3 a, a concave-convex order of the second line is reversed relative to the first line. Particularly, along the first line, the first convex surface 44 is disposed on the left and the first concave surface 40 is disposed on the right, while along the second line, the second concave surface 46 is disposed on the left and the second convex surface 42 is disposed on the right. In this way, the second convex surface 42 corresponds with the first concave surface 40 and the second concave surface 46 corresponds with the first convex surface 42.

Similarly, FIG. 3 b shows the connection surface of the second block 12. Specifically, the connection surface includes a first convex surface 50 and a first concave surface 54 extending along a first horizontal line, and a second concave surface 52 and a second convex surface 56 that extends along a second horizontal line parallel to the first line. The first and second convex surfaces 50, 56 have an outward “V” profile, and the first and second concave surfaces 54, 52 have a complementary inward “V” profile, so that the first convex surface is complementary to the first concave surface, and the second convex surface is complementary to the second concave surface. In block 12, the first concave surface 54 is also complementary to the second convex surface 56, and the second concave surface is also complementary to the first convex surface 50.

Further, as with the first block 10, a concave-convex order of the second line in block 12 is reversed relative to the first line. Thus, along the first line, the first convex surface 50 is disposed on the left and the first concave surface 54 is disposed on the right, while along the second line, the second concave surface 52 is disposed on the left and the second convex surface 56 is disposed on the right. The second convex surface 56 corresponds with the first concave surface 54, and the second concave surface 52 corresponds with the first convex surface 50. The second block 12 in this example embodiment also has upper and lower flat surfaces 58, 59.

Referring again to FIG. 3 a, a first axis 70 extends (as shown, vertically) between the first convex surface and the first concave surface. The first concave surface 40 is substantially a reflection of the first convex surface 44 about the first axis 70. Further, the first axis 70 extends between the second convex surface 42 and the second concave surface 46. The second concave surface 46 is substantially a reflection of the second convex surface 42 about the first axis 70. As used herein, “substantially” refers to meeting or approximating a condition sufficiently to provide a particular benefit, subject to manufacturing tolerances, natural or designed imperfections, deliberate aesthetic features, etc.

Additionally, in block 10, a second axis 72 extends (as shown, horizontally) between the first convex surface 44 and the second concave surface 46. The second concave surface 46 is substantially a reflection of the first convex surface 42 about the first axis 72. The second axis 72 also extends between the second convex surface 42 and the first concave surface 46. The first concave surface 46 is substantially a reflection of the second convex surface 42 about the second axis. Similar axes can be defined for block 12.

FIG. 2 a shows two engagements of the example connection surfaces for the blocks 10, 12. A first engagement 22 is formed where convex surface 50 of block 12 is received in concave surface 40 of block 10. A second engagement 24 is formed where convex surface 42 of block 10 is received in concave surface 52 of the second block 12. The complementary surfaces of the units engaging at 22, 24 forms a general S-shape as can be seen in FIG. 2 a, herein referred to as an “S-connection.” This S-connection restrains vertical movement between the blocks 10, 12.

Similarly (but reversed in direction), FIG. 2 b shows an engagement 32 wherein convex surface 44 of block 10 is received by concave surface 54 of block 12. A second engagement 34 is formed where convex surface 56 of block 12 is received in concave surface 46 of block 10. The complementary surfaces of the two units engaging at 32, 34 also forms a general S-shape, albeit reversed, which also restrains vertical movement.

Together, the S-connections of the vertical halves 14, 18 may be referred to as a “double S-connection.” Further, because the S-connections of the vertical halves are reversed with respect to one another, lateral movement of the blocks 10, 12 with respect to one another is constrained as well. Thus, the double S-connection restrains both vertical and horizontal movement between the blocks 10, 12.

In the embodiment of FIGS. 1-3 the “S” shape of the connection in the vertical plane is angular as shown in FIGS. 2 a and 2 b. However, in other embodiments, as will become more apparent below, the “S” shape maybe smoothly curved, box-shaped, regular or irregular. Herein, the term “S-shape” or “S-connection” is used in its broadest sense to mean any shape that is a center 180 degree rotation having one end that is generally convex and the other end being a substantially concave reflection thereof.

Further, in this embodiment, the mating block faces include upper flat surfaces 48, 58 that engage at 26 in FIG. 2 a, and the lower flat surfaces 49, 59 engage at 28. In the present embodiment the surfaces engaging at locations 22, 24, 26, 28, 32, 34 may engage closely as shown, which would prevent the transmission of light, sand, soil or other materials from one side of the block to the other. However, in other embodiments, a gap may be provided between one or more of the surfaces between the blocks 10, 12. The gap(s) can remain open to provide permeability or can be filled with other materials, such as neoprene, plastic or other resilent materials during manufacture or installation. Also, one or more engagements can be weight-bearing.

Because the convex/concave surfaces are reflections of one another about the vertical and horizontal axes, the orientation of the mating surface will be the same even when the block is inverted. Thus, for example in the embodiment of FIGS. 1-3, if block 12 is flipped over, it will still connect with block 10. This is especially valuable for connecting non-rectangular blocks, e.g., trapezoidal and asymmetric shapes, as will be appreciated by persons skilled in the art.

Various embodiments of structural units may have one or more connection surfaces. Further, one or more connection surfaces may be disposed at any structural unit face (plane, curved, irregular, or other outer face of the structural unit), or in any portion or portions of a face, and in any orientation. For example, a structural unit may have ends, sides, top, bottom, or any other face with one or more connection surfaces. Such connection surfaces can occupy an entire face of a unit, or only a portion of the structural unit face. Further, double S-connection surfaces can be centered on a face, or can be off-center. All combinations of connection surfaces, connection surface features (e.g., connection surface features shown or described in any embodiment herein), connection surface locations on a structural unit face, and orientations are contemplated including but not limited by the several embodiments shown and described herein. Structural units can be connected end to end forward, turned, or flipped, or otherwise connected in any combination to form surface coverings, walls, edges and combinations thereof.

Connection surfaces can be provided on the face of the structural unit, such as but limited to by being formed, e.g., molded or otherwise formed, into one or more faces of the structural unit. For example, FIGS. 4-5 show second embodiment structural units 80 having a double S-connection surface formed therein.

Structural units can comprise, as non-limiting examples, pavers, concrete masonry units (CMU), retaining wall blocks, patio stones and edgers. Example structural units, including connection surfaces, may be manufactured in any manner of substantially any material such as, but not limited to, concrete (including wet cast and dry cast), clay, plastic, ceramic, glass or composite materials. Wet cast and dry cast concrete are preferred for building units, such as pavers, CMU, retaining wall blocks, patio stones and edgers, curbs, caps, precast wall panels, revetment mats, and other units.

FIG. 6 shows a structural unit 84 according to a third embodiment having a double S-connection surface. FIG. 7 shows the connection surface of structural unit 84 facing juxtaposed to a second, like structural unit 86, illustrating how the surfaces can engage.

FIG. 8 shows a structural unit 88 according to a fourth embodiment. Unit 88 has a first S-connection having a convex surface 90 and complementary concave surface 92 that are in the shape of a triangular prism. A second S-connection including convex surface 94 and complementary concave surface 96 has a similar shape to convex surface 90 and concave surface 92 but includes a beveled edge to define truncated pyramids. As demonstrated by this embodiment, the configurations of the two S-connections need not be the same. Further, the two S-connections need not have the same depth dimension. For example, the convex portion 94 of the truncated pyramid-shape S-connection could project outwardly a greater distance than the convex portion 90 of the triangular prism-shaped S-connection to provide a spacing effect, or the convex portion could have a shorter depth for creating space or allowing movement.

The first and second convex and concave surfaces can be any of various three-dimensional shapes, including solid geometric shapes or irregular shapes. The convex and concave surfaces can include at least one partial geometric solid. In some embodiments, for instance, structural units can be configured to have a more natural appearance, and thus include imperfections, textures, slight mismatches, etc. The first concave surface, the first convex surface, the second concave surface, and/or the second convex surface can have a textured or non-textured outer surface. Example surfaces can have irregular rock-like surfaces. The shapes can also vary for particular applications, as will be appreciated by those skilled in the art having reference to the present disclosure.

Rounded and/or irregular profiles provide a more natural, stone-like appearance. For example, FIG. 9 shows a structural unit 100 according to a fifth embodiment having a double S-connection surface that is generally rounded and irregular to provide a natural, rock-like appearance. The rounded double S-connection surface includes convex curved surface 104, which transitions to a concave curved surface 106 along line S₁. The surfaces 104, 106 are disposed between first 102 and second 108 generally rock-like surfaces 108. Similarly, a convex curved surface 116 transitions to a concave curved surface 114 along line S₂, parallel to line S₁. The second portion is disposed between rock-like surfaces 112, 118. There is also a continuous transition laterally between convex curved surface 104 and concave curved surface 114 along horizontal line S₃, and laterally between concave curved surface 106 and convex curved surface 116 along horizontal line S₄. In this way, the lateral profiles of block 100 are also S-shaped along directions S₃ and S₄. Lines S₃ and S₄ are substantially perpendicular to lines S₁ and S₂. The convex and concave surfaces along lines S₁, S₂, S₃, S₄ each define rounded, irregularly shaped S-profiles. The numbering of lines S₁-S₄ is merely for convenience and does not reflect priority or sequence. For example, lines S₃ and S₄ can be considered as first and second lines.

The S-profiles of lines S₁, S₂ are preferably symmetrical but reversed with respect to one another, as is the case with lines S₃ and S₄. However, it is not necessary that the profiles of S₁, S₂ be the same as S₃, S₄. Indeed, as one can observe from FIG. 9, S-connections S₁, S₂ are shorter in length than S-connections S₃, S₄. Although it is not strictly necessary, it is preferred that the general configuration of the convex and concave surfaces along lines S₃ and S₄ are complementary with one another. Further, in the block 100 embodiment, the configurations of convex-concave surfaces 104,106 and convex-concave surfaces 116, 114 are reflections of one another about a horizontal axis. Thereby, one unit 100 can be flipped top-to-bottom and still mate with another unit 100.

Structural units can be of essentially any shape. Example shapes include rectangular, trapezoidal, cruciform, glides, hexagonal or other polygonal, other geometric shapes, and irregularly shaped units. Double S-connection surfaces can be advantageously employed to connect and interlock adjacent structural units in a wide variety of structures, including but not limited to interior and exterior walls, retaining walls, pre-cast wall panels, caps, columns and other vertical structures, as shown for example in U.S. Pat. Nos. 3,394,521, 4,107,894, 6,557,818, 6,615,561 and 7,011,474; pavements, patios, walkways and other surface coverings as shown for example in U.S. Pat. Nos. 4,128,357, 4,919,565 and 7,393,155; edgers and curbs, as shown for example in U.S. Pat. No. 7,637,688; revetment mats, coast fortifications, and other protective structures, as shown for example in U.S. Pat. Nos. 6,558,074 and 6,863,472. Double S-connection surfaces can be used to join different size or shape structural units in multi-unit systems, as shown for example in U.S. Patent Publication No. 2005/0166517. All of the foregoing cited patents and publications are hereby incorporated by reference. Double S-connectors have particularly advantageous application in tessellated surface coverings comprising glides, flip glides, rotations, and other types of tessellations—both regular and irregular. Further, double S-connection surfaces can be utilized to join different types of structures, such as walls-to-pavers, and pavers-to-curbs, as shown in FIG. 32, for example.

FIGS. 10-13 show example structural units 120, 122 according to the fifth embodiment that are generally trapezoidal in plan view and have opposing ends with irregular double S-connection surfaces. In FIG. 10, first ends 124 of structural units 120, 122 are juxtaposed. In FIG. 11, first end 124 of structural unit 120 is juxtaposed with a second end 126 of structural unit 122. FIG. 12 shows a course in which the structural units 120, 122 are connected first end to first end to form an angle. Additional units 120, 122 can be connected to form a segmented arc or circle. FIG. 13 shows a course in which the structural units 120, 122 are connected first end to second end to form a straight line. This effect can be achieved by flipping one unit top-to-bottom or turning one unit 180 degrees. Also, in a preferred embodiment, units 120, 122 include false joints that contribute to the natural rock-like appearance. Further, the connecting faces of the units 120, 122 do not engage tightly leaving gaps of variable width but substantially the same size and appearance as the false joints so that the mating faces between units are not readily apparent.

Structural units may be respectively arranged in rows, courses, columns, orthogonally, setback, rotationally, serpentine, or other arrangements. In example wall embodiments, the structural units are arranged to provide at least a second course on top of a first course. One or more double S-connection surfaces can be provided on the top and bottom faces of the units to thereby restrain movement between units in the horizontal plane. The structural wall units may also include double S-connection surfaces on the ends or sides of the units to thereby restrain movement between units in a vertical plane. Structural wall units in the second course are preferably staggered from left to right with respect to the structural units in the first course. Examples of staggered arrangement include, but are not limited to, running bond, half bond, quarter bond, three-quarter bond, etc. For example, FIGS. 14-17 show wall sections including three blocks 130, 132, 134 according to the fifth embodiment. The blocks 130, 132, 134 are arranged in lower and upper courses having a half-bond arrangement. Other, non-staggered arrangements are possible, including stack bond arrangements. Blocks can be in a vertical (near vertical) or setback arrangement as well. Optionally, connection surfaces can be provided on top or bottom faces to provide connection between courses, on faces, or both for front-to-back connection. Courses with such connection surfaces can be connected in a running bond, quarter bond, three-quarter bond or other arrangements.

FIGS. 18-22 show structural units 140, 142 according to a sixth embodiment, in which the structural units are generally trapezoidal and have double S-connection surfaces on opposing end faces. FIGS. 18-19 show the structural units 140, 142 respectively in reverse orientation so that they are connected (FIG. 19) end-to-end in a straight line. FIGS. 20-22 show the structural units 140, 142 having the same orientation so that they are connected (FIG. 22) end-to-end to form an angle. Complex courses, such as serpentine courses, and structures having such courses, can be provided by varying the orientation of arranged structural units.

FIGS. 23 a-23 b show a structural unit 150 according to a seventh embodiment in which edges 152, 154 of convex surfaces 156, 158 are partially beveled to aid installation by guiding adjacent structural units into final position. More specifically, in the FIG. 23 embodiment, convex surface 156 comprises a triangular prism having a substantially vertical end 162 (best viewed in FIG. 23 b) and a beveled surface 160. Optionally, the beveled surface 160 can extend all the way to the bottom of the concave portion.

FIGS. 24 a-24 c show a structural unit 170 according to an eighth embodiment. In this embodiment, a double S-connection is formed by off-setting faces 172, 174 such that convex portion 176 is aligned with concave portion 182 and convex portion 178 is aligned with concave portion 184. A gap 180 is provided between the faces 172, 174 for adjustment. The gap can be filled with alternative materials, such as neoprene, plastic, etc., either during manufacture or during installation. Alternatively, the gap can be left open.

FIG. 25 shows double S-connection surfaces 202, 204 disposed on the ends of structural units 206, 208 according to a ninth embodiment. The connection surfaces 202, 204 include convex and concave surfaces that are generally cubic or rectangular-prism shaped. As discussed above, the “S” connection shape need not be a smooth curve, but can be block format as in this embodiment. The connection surfaces are disposed over the entire face, though in other embodiments, the connection surfaces can be disposed over less than the entire face. The fit between units need not be perfect, and can be intentionally imperfect for aesthetic and/or functional purposes.

FIG. 26 shows complementary connection surfaces 210, 212 disposed at end faces of structural units 214, 216 according to a tenth embodiment. The connection surfaces 210, 212 include convex and concave surface that are a partial/truncated cylindrical shape. Connection surfaces can be load-bearing due to engagement of complementary surfaces.

FIG. 27 is a plan view of a structure 220 according to an eleventh embodiment that comprises a plurality of cruciform structural units 222 assembled to form a panel or mat. The structural units 222 are connected to one another via double S-connection surfaces 224, two exemplary pairs being shown in FIG. 27. FIG. 28 is a plan view of structure 230 according to a twelfth embodiment including hexagonal structural units 232, connected to one another via pairs of double S-connection surfaces 234 (two exemplary pairs are shown in FIG. 28). Additional pairs of connector can be used as will be appreciated by those of ordinary skill in the art. Mat structures can be used in highway walls or embankments, waterway linings or banks, as shore protection, or other applications as known in the art. The double S-connections of the invention has particular application in waterways, as the double S-configuration provides both lateral and vertical restraint between units, which can prevent or reduce over-tipping, wherein rapidly flowing water over the surface exerts an up-force on the downstream edges of the structural units.

A surface covering, mat or panel structure can include openings in various shapes, e.g., geometric or irregular. The openings can be formed within units or can be defined spaces or gaps between structural units. The openings can be left as an open space, filled with permeable materials such as sand, filled organic materials such as soil and plants, filled with cement, gout or other adhesives, filled with cushioning materials, or even filled with secondary units, which can in some embodiments have a different shape, material composition and/or surface treatment as compared to the primary structural units. Connection surfaces on the mating sides of the joined structural units provide an easy connection. Structural units combined in this way, with or without secondary elements or other materials in openings, can be arranged to define various patterns, providing aesthetic qualities. Individual structural units, or groups of combined structural units, alone or with secondary elements disposed within openings, could be assembled as mats or panels. Cabling can run between structural units, for instance as shown in U.S. Pat. No. 6,558,074.

FIG. 29 is a plan view of a glide structure 240 according to a thirteenth embodiment comprising a plurality of curved structural units 242 connected to one another via pairs of connection surfaces 244 (two exemplary pairs are shown).

FIG. 30 shows a portion of a surface covering 250 including at least two surface covering units 252 according to a fourteenth embodiment. The surface covering units 252 are irregular rotational tessellation elements made in accordance with U.S. Pat. No. 7,393,155. One or more pairs of double S-connection surfaces 254 are provided to connect the units 252. These connection surfaces 254 can be split along a face of the surface covering units 252.

The double S-connection surface of the invention has particular application to surface coverings units such as pavers and patio stones. The double S-connection surfaces 250 provide a double lock, restraining adjacent units from moving vertically with respect to one another in addition horizontal restraint that typically provided in conventional horizontal interlocking systems. This can prevent a individual units in a surface covering from tipping, sinking or being thrust upward due to an inconsistent foundation, erosion, frost heave, or other causes. Further, a pavement can be made permeable, e.g., water-permeable, if desired, or substantially impermeable to light, sand, soil, etc.

FIG. 31 shows a structural unit 260 according to a fifteenth embodiment. Unit 260 has connection surfaces 262 a , 262 b , 262 c , 262 d , 262 e , 262 f disposed on all sides (three are visible in FIG. 31). It is also contemplated that the connection surfaces could be on fewer than all sides, and on an interior portion of a particular side or sides. While the structural unit 260 profile generally defines a cube 264, the connection surfaces 262 a -f in unit 260 are configured to provide a “natural” irregular double S-connection. Among other advantages, such a configuration allows multiple units 260 to stacked on a skid with adjacent units interlocking with each other in both vertical and horizontal directions. Thereby, the units “hug” one another reducing abrasion between units, breakage and other damage in transportation. It is not required for all surfaces of the building blocks 260 (or other structural units disclosed herein) to touch, and gaps can be provided between units. Preferably, the connection surfaces 262 a , 262 b , 262 c , 262 d , 262 e , 262 f are configured to be substantially the same so that all faces of the unit 260 can mate with all faces of similarly configured units.

Structural units connected by double S-connection surfaces may be of the same type, or of different types. FIG. 32 shows an example structure 270 according to a sixteenth embodiment, including a wall structural unit 272 that is connected to a paver structural unit 274, which is in turn connected to a curb structural unit 276. Mating double S-connection surfaces 278 disposed on opposing faces of the units 272, 274, 276 connect the units, and thus different types of structures, to one another. Any combinations of two or more structural unit types are contemplated herein. Non-limiting examples include wall systems to paver systems, retaining wall systems to paver systems, edger systems to patios, walls to pavers and edgers, walls to caps, pavers to curbings, precast wall panels to pavers, walls to revetment mats, etc. Those of ordinary skill in the art will appreciate suitable positions for connection surfaces for mating structural units of different types.

The position of the connection surface on a face of a structural unit can be over the entire face, or a portion of a face. Further, where the connection surface is disposed on a portion of a face, the connection surface can be disposed at any location on the structural unit face. As one example, FIG. 33 shows a structural unit 280 according to a seventeenth embodiment having a connection surface 282 disposed on an end face 284, and located at a central interior portion. The connection surface 282 can be disposed away from the center of the face in other embodiments.

FIG. 34 shows a wall structure comprised of a plurality of structural panel units 290 according to an eighteenth embodiment. The panel units 290 include double S-connection surfaces 292 disposed at each of four end faces 294. Preferably the double S-connection surface is centered on each end face. Accordingly, each panel unit can be assembled in the same direction, alternative directions, i.e., parquet as shown, or quarter turn.

Structural units can have more than one double S-connection on a single face. FIG. 35 shows a structural unit 300 according to a nineteenth embodiment having a pair of double S-connection surfaces 302, 304 disposed on an end face 306 of the structural unit 300. The connection surfaces 302, 304 can be configured as images rotated about center line 308. It is also contemplated to split the connection surface in half vertically, so that, for instance, a single S is on top and a single S is on bottom. The connection surface can also be split in half horizontally. Third, fourth, or additional double S-connection surfaces can also be provided on a single building unit surface or on a combination of faces. When multiple double S-connection surfaces are employed, each connector need not be the same size or shape as the other S-connection surfaces. A full double S can be disposed on top and bottom portions of the face 306, or a double S can be split and disposed such that half is on top and half is on bottom, provided that the halves are substantially equidistant from the center line 308.

FIG. 36 shows a structural unit 310 according to a twentieth embodiment having a double S-connection surface disposed on a face 306. The double S-connection surface is split into first and second portions 316 a , 316 b , each of which are substantially equidistant from a center line 308. This arrangement helps resist tipping or twisting of connected units. In the FIG. 36 embodiment, centers of the first and second portions 316 a , 316 b are separated from respective left and right edges at a quarter of the distance across the length of the face 306, so that the center of first portion 316 a is separated from each of the left edge and from the center line 308 by a distance A, and the center of second portion 316 b is separated from each of the center line 308 and the right edge by the same distance A. Split portions alternatively can be disposed horizontally or vertically adjacent to one another. Optionally and preferably, the double S-connection surfaces are spaced along the side face of the unit so that the units can be assembled in ¼, ½, ¾ or stacked bond relationship.

FIG. 37 shows a structural unit 320 according to a twenty-first embodiment having two sets of double S-connection surfaces 322 on each end face 324. Any number of pairs or sets can be provided. As provided above, one or more single units can also be split down a center as well. This arrangement may be used to generate recessed panels (I), projecting panels (P) or slanting panels (S) in a wall or panel structure as shown in FIG. 38. Specifically, by selectively mating inner connecting surfaces with outer connecting adjacent panels can be recessed, projected or slanted relative to each other. As one example, curves can be provided by progressively stepping panels in/out relative to each other. Spaces may be provided between concave surfaces and complementary convex surfaces, in vertical and/or horizontal directions. FIG. 39 shows a structural unit face 336 according to a twenty-third embodiment, in which partial cylindrical convex surface 338 and complementary concave surface 340 surfaces are separated from one another by spaces 342. FIG. 40 shows another unit face 350 according to a twenty-fourth embodiment similar to connection surface 336, but with truncated pyramid shaped convex 338 and complementary concave 340 surfaces.

While some example embodiments include double S-connection surfaces that are integrated, e.g., formed, into a face of a structural unit, other embodiment double S-connection surfaces can be alternatively or additionally provided by external elements that are disposed on the face and are attached, adhered or otherwise coupled to the face. External elements may include, as non-limiting examples, convex and concave surfaces formed in any suitable manner, such as by molding into an external face. The concave and convex surfaces of such connection surfaces can be configured similarly to any of the other concave and convex surfaces shown or described elsewhere herein.

External elements may also be used as a key, and connected to a receiving hole. For example, FIG. 41 shows two convex faces 350, 352 according to a twenty-fifth embodiment. The convex faces 350, 352 include insets 354, 356, in which are disposed external double S-connection surfaces 358. For example, the external connection surfaces 358 may be plugged into the insets 354, 356, which provide a receiving core for the connection surfaces. The connection surfaces 358 are configured according to any of the connection surface embodiments disclosed herein. Alternatively, the connection surface 358 can be integrated into the faces 350, 352. FIG. 42 shows a convex face 360 and a concave face 362 according to a twenty-sixth embodiment, which include opposing insets 364, 366, each of which has an external double S-connection surface 368 disposed therein. The connection surface 368 can be configured similarly to the external connection surface 358.

Example connection surfaces can be configured to allow some movement in one direction providing a tighter restraint in another direction. For example, FIG. 43 shows two structural units 370, 372 having connection surfaces 374, 376 configured such that a space 378 is defined between the units either along a vertical direction (as shown in FIG. 43) or in a horizontal direction. One S is visible in FIG. 43. The other S (not shown) preferably has substantially the same spacing. Such a space can be provided by controlling manufacturing tolerances, for instance, making the concave surfaces deeper than the convex surfaces. Alternatively, the concave surfaces can be made longer than the convex surfaces. In the embodiment shown in FIG. 43, the space 378 allows the structural units 370, 372 to move in a vertical direction with respect to one another, while still constraining movement along the horizontal direction. The space 378 can be fully or partially filled with material, e.g., a pad (not shown) e.g., for cushioning, or may be a clear space. To allow movement in the later direction, a space may be provided such as space 180 (see FIG. 24 b). A pad or other material may be provided in the space 180.

Example connection surfaces, structural units, and structures can include any combination of features shown and/or described herein. The particular connection surface shown and described herein are merely examples, and those of ordinary skill in the art will appreciate that many other configurations for connection surfaces are possible, and such additional configurations are intended to fall under the scope of the present invention.

Structures can be or include vertical, horizontal, flat, curved, complex or irregular, largely two-dimensional, and/or largely three-dimensional structures. Structures can include a plurality of structural units, including any of the structural units shown or described herein, including any combinations of structural units, and including any of the connection surfaces, including combinations of connection surfaces, shown or described herein. The structure may be a complete, stand-alone structure, or may be combined with other structural units to provide a larger structure. Example structures include, but are not limited to, walls (e.g., retaining walls, interior walls, exterior walls, sound walls, etc.), wall veneers, wall panels, column blocks highway panels, other panels, pavements, edges or combinations thereof.

While various embodiments of the present invention have been shown and described, it should be understood that other modifications, substitutions, and alternatives are apparent to one of ordinary skill in the art. Such modifications, substitutions, and alternatives can be made without departing from the spirit and scope of the invention, which should be determined from the appended claims.

Various features of the invention are set forth in the appended claims. 

What is claimed is:
 1. A connection surface disposed on at least one face of a structural unit, the connection surface comprising: a first convex surface and a first concave surface, the first convex surface and first concave surface being arranged substantially along a first line, the shape of the first concave surface being complementary to the shape of the first convex surface; and a second convex surface and a second concave surface, the second convex surface and second concave surface being arranged substantially along a second line that is substantially parallel to the first line, the shape of the second concave surface being complementary to the shape of the second convex surface; wherein a concave-convex order of the second line is reversed relative to the first line such that the second convex surface corresponds to the first concave surface and the second concave surface corresponds to the first convex surface.
 2. The connection surface of claim 1 wherein a first axis extends between the first convex surface and the first concave surface and the first concave surface is substantially a reflection of the first convex surface about the first axis; and wherein the first axis extends between the second convex surface and the second concave surface and the second concave surface is substantially a reflection of the second convex surface about the first axis.
 3. The connection surface of claim 1 wherein the first concave surface is complementary to the shape of both the first and second convex surfaces and the second concave surface is also complementary to the shape of both the first and second convex surfaces.
 4. The connection surface of claim 3, wherein a first axis extends between the first convex surface and the first concave surface and the first concave surface is substantially a reflection of the first convex surface about the first axis; and wherein the first axis extends between the second convex surface and the second concave surface and the second concave surface is substantially a reflection of the second convex surface about the first axis; and wherein a second axis, perpendicular to the first axis extends between the first convex surface and the second concave surface and the second concave surface is substantially a reflection of the first convex surface about the first axis; and wherein the second axis extends between the second convex surface and the first concave surface and the first concave surface is substantially a reflection of the second convex surface about the second axis.
 5. The connection surface of claim 3, wherein the first convex surface and the second concave surface are arranged substantially along a third line; the first concave surface and the second convex surface are arranged substantially along a fourth line; the third and fourth lines being substantially parallel; and the third and fourth lines being substantially perpendicular to the first and second lines.
 6. The connection surface of claim 1 wherein the first and second convex surfaces and first and second concave surfaces each comprise at least one partial geometric solid.
 7. The connection surface of claim 1 wherein the first and second convex surfaces and first and second concave surfaces each comprise irregular rock-like surfaces.
 8. The connection surface of claim 1 wherein the connection surface is an interior portion of the at least one face of the structural unit.
 9. The connection surface of claim 1 wherein the first convex and first concave surfaces together define a first S profile, and wherein the second concave and second convex surfaces together define a second S profile that is symmetrical but reversed with respect to the first S profile.
 10. The connection surface of claim 9 wherein the first convex and second concave surfaces together define a third S profile, and wherein the second concave and first convex surfaces together define a fourth S profile that is symmetrical but reversed with respect to the third S profile.
 11. A structural unit comprising: a plurality of faces; at least one connection surface disposed on at least two of the plurality of surfaces; wherein each connection surface comprises: a first convex surface and a first concave surface, the first convex surface and first concave surface being arranged substantially along a first line, the shape of the first concave surface being complementary to the shape of the first convex surface; and a second convex surface and a second concave surface, the second convex surface and second concave surface being arranged substantially along a second line that is substantially parallel to the first line, the shape of the second concave surface being complementary to the shape of the second convex surface; wherein a concave-convex order of the second line is reversed relative to the first line such that the second convex surface corresponds to the first concave surface and the second concave surface corresponds to the first convex surface.
 12. The structural unit of claim 11 wherein the unit has a first and opposite second face, each said face having a connection surface thereon.
 13. The structural unit of claim 11 wherein the first convex and first concave surfaces together define a first S profile, and wherein the second concave and second convex surfaces together define a second S profile that is symmetrical but reversed with respect to the first S profile; and wherein the first convex and second concave surfaces together define a third S profile, and wherein the second concave and first convex surfaces together define a fourth S profile that is symmetrical but reversed with respect to the third S profile.
 14. A structure comprising: a plurality of structural units including at least first and second structural units, each of the plurality of structural units comprising a plurality of faces including at least a first and second face, each of which having at least one connection surface; wherein each connection surface comprises: a first convex surface and a first concave surface, the first convex surface and first concave surface being arranged substantially along a first line, the shape of the first concave surface being complementary to the shape of the first convex surface; and a second convex surface and a second concave surface, the second convex surface and second concave surface being arranged substantially along a second line that is substantially parallel to the first line, the shape of the second concave surface being complementary to the shape of the second convex surface; wherein a concave-convex order of the second line is reversed relative to the first line such that the second convex surface corresponds to the first concave surface and the second concave surface corresponds to the first convex surface; wherein connection surfaces of the first and second structural units are coupled such that the first and second concave surfaces of the connection surface of the first structural unit are at least partially receive the first and second convex surfaces of the connection surface of the second structural unit, and such that the first and second convex surfaces of the connection surface of the second structural unit at least partially receive the first and second convex surfaces of the connection surface of the first structural unit.
 15. The structure of claim 14 wherein a gap is defined between mating faces of the first and second structural units, and wherein the gap is at least partially filled with a resilient material. 